Although gas lamps and the ignition of gas burners dates back many years, in more recent times gas lamps have been used as outdoor lighting in residential neighborhoods to provide aesthetic and safety lighting near the residences. Until the recent increases in flammable gas prices, in most instances natural gas, such "yard lights" were frequently installed with the general plan that they would be lighted manually and burn continuously i.e. day and night. The cost of natural gas was low relative to electricity and the cost of fuel for such gas lamps was considered more or less inconsequential compared to the convenience and safety of having a lighted yard during all of the hours of darkness. In recent years the cost of natural gas has increased to the point where a relatively fewer number of yard lights are being installed. In many neighborhoods, previously installed outdoor as lamps have been turned off. Many have been replaced with electric lamps and others remain unused.
The economic situation for the use of these lamps, is substantially improved if these gas burning lamps are equipped to be turned off in the morning, or as natural daylight increases sufficiently, and turned on in the evening when the natural daylight reduces to the point that they have useful value. It is an object of this invention to provide automatic control mechanisms and circuits to operate a gas appliance and particularly an outdoor yard light automatically and to meet the need as described above.
The automatic control of gas ignition is well known in the art. Examples of systems suitable for automatic fuel gas ignition are given in U.S. Pat. No. 3,154,135 to La Pointe, U.S. Pat. No. 3,196,928 to La Pointe et al, and U.S. Pat. No. 4,298,335 to Riordan. Such systems typically accomplish their automatic start-up sequence in response to either thermostatic element or manual contact input signals.
Ignition control of illuminating gas systems is generally known and examples of such systems are given in U.S. Pat. No. 3,358,474 to Liesse and U. K. Patent Application No. GB 2074713A. Such illuminating systems have generally been electrical in nature but are responsive in their operation to manual contact initiation.
I have discovered that illuminating gas lamps and the like may be advantageously constructed and operated to automatically ignite in response to surrounding light conditions s as to be activated by diminishing or diminished environmental light and additionally to be shut-off by the presence of adequate surrounding light.